1. Field of the Invention
The invention relates to a method and apparatus which permits the insertion of text of two languages whose characters proceed in two opposite directions on a CRT display screen. More specifically, the invention relates to such a method and apparatus which is transparent to higher level software, specifically, the operative systems and application programs.
2. Description of Prior Art
At times, when applying a primary text, of a primary language, whose characters proceed in a primary direction (e.g., a Latin text which proceeds from left to right) on a CRT display screen, it may be necessary to make an insertion of a secondary text of a secondary language whose characters proceed in a secondary, different direction (e.g., an Arabic text whose characters proceed from right to left or Japanese which is vertical). Under present methods, and with the present apparatus, the procedures for processing and handling the secondary language must be included as steps in the operating system or the application software. Thus, each time a different operating system or application program is used which requires such insertion, the steps for handling of the secondary language must be included in that different operating system or application program. It is therefore clear that the present apparatus and method do not include a single piece of either hardware or software which is portable, i.e., will automatically be applied as appropriate to any operating system or application software without requiring additional specific program steps. This is, of course, inconvenient in that the procedures must be written into each operating system or application program.